3 The Divisions of Infectious Disease and General Medicine, and the Medical Practice Evaluation Center, Department of Medicine, Massachusetts General Hospital and the Harvard University Center for AIDS Research, Harvard Medical School, Boston, MA, U.S.A

Abstract

Background

While Brazil has had a long-standing policy of free access to antiretroviral therapy
(ART) for all in need, the epidemiological impact of ART on human immunodeficiency
virus (HIV) RNA suppression in this middle-income country has not been well evaluated.
We estimate first-line ART effectiveness in a large Brazilian cohort and examine the
socio-demographic, behavioral, clinical and structural factors associated with virologic
suppression.

Methods

Virologic suppression on first-line ART at 6, 12, and 24 months from start of ART
was defined as having a viral load measurement ≤400 copies/mL without drug class modification
and/or discontinuation. Drug class modification and/or discontinuation were defined
based on the class of a particular drug. Quasi-Poisson regression was used to quantify
the association of factors with virologic suppression.

Results

From January 2000 through June 2010, 1311 patients started first-line ART; 987 (75%)
patients used NNRTI-based regimens. Virologic suppression was achieved by 77%, 76%
and 68% of patients at 6, 12 and 24 months, respectively. Factors associated with
virologic suppression at 12 months were: >8 years of formal education (compared to
<4 years, risk ratio (RR) 1.13, 95% confidence interval (95% CI) 1.03-1.24), starting
ART in 2005-2010 (compared to 2000-2004, RR 1.25 95% CI 1.15-1.35), and clinical trial
participation (compared to no participation, RR 1.08 95% CI 1.01-1.16). Also at 12 months,
women showed less virologic suppression compared to heterosexual men (RR 0.90 95%
CI 0.82-0.99). For the 24-month endpoint, in addition to higher education, starting
ART in the later period, and clinical trial participation, older age and an NNRTI-based
regimen were also independently associated with virologic suppression.

Conclusions

Our results show that in Brazil, a middle-income country with free access to treatment,
over three-quarters of patients receiving routine care reached virologic suppression
on first-line ART by the end of the first year. Higher education, more recent ART
initiation and clinical trial participation were associated with improved outcomes
both for the 12-month and the 24-month endpoints, suggesting that further studies
are needed to understand what aspects relating to these factors lead to higher virologic
suppression.